Method and apparatus for use in shoemaking employing heat



Sept. 1942- G. F. RYAN METHOD AND APPARATUFOR USE IN SHOEMAKINGEMPLOYING HEAT 2 Sheets-She a 1 Filed July 29, 1940 Sept. 1, 1942. RYAN2,294,481

METHOD AND APPARATUS FOR USE IN SHOEMAKING EMPLOYING HEAT FiledJuly 29,1940 2 Sheets-Sheet 2 0 I Z M /a //v VE/V TUE? F Patented Sept. 1, 1942METHOD AND APPARATUS FOR USE IN SHOEMAKING EMPLOYING HEAT George F.Ryan, South Peabody, Mass, assigncr to United Shoe MachineryCorporation, Flemington, N. J a corporation of New Jersey ApplicationJuly 29, 1940, Serial No. 348,083

Claims.

This invention relates to improved methods and apparatus for use inshoemaking and involving the use of heat.

At many stages in the manufacture of shoes time is lost owing to thenecessity for allowing the shoe or a part of it which is about to beoperated upon to dry. For example, it is necessary in the use of manycommon types of cement for attaching theoutsole to a shoe, that thecement which is applied to the shoe bottom be allowed to dry until it istacky. The heeling operation also is delayed to permit substantialdrying of the outsole in those cases where the outsole has been mulledto facilitate the sole laying and channeling operations. Similarly,further delay may occur when a breast flap is secured to the heel by theuse of a cement which must have at least begun to set before the flapcan be permanently secured to the heel. Then, too, sole edges andbottoms cannot be finished until the wax, paint or other liquidfinishing medium which is used in connection with these operations hasdried.

While the time lost per shoe at any single operation is small, thecumulative effect of such delays is material, entailing the use of morelasts and other equipment than would otherwise be necessary and causingcongestion of racks of shoes to be operated upon wherever the delaysoccur. For these reasons, there is a general slowing down of the flow ofshoes through the factory.

Moreover, the necessity for having shoes in a substantially drycondition at many different times during their manufacture discouragesthe use of mulling to the most effective degree; and in cases where thecost factor is more important than that of quality, mulling is oftendispensed with entirely, even at those operations Where its use would bemost beneficial.

In view of the foregoing, an object of the invention is to reduce to aminimum the time lost due to drying of shoes or their parts throughouttheir manufacture and to provide a general improvement in their quality.

To this end, the invention contemplates the use of a heat retaining andconducting form or last on which the shoe is placed and provides in oneaspect an improved method of shoe making characterized by heating theform between successive operations on the same shoe to maintain thetemperature of the form and the shoe substantially uniform throughoutthe interval during which the operations are performed.

By thus maintaining the shoe at a drying temperature throughout or for arelatively long period in its manufacture, mulled shoe parts, up-

on being applied to the shoe, dry so quickly as not to delay anysucceeding operation. Similarly, cements or finishing materials set ordry so soon after their application to the heated shoe that thecorresponding attaching or finishing operations may be performed on thefirst shoe in even a small rack as soon as the last shoe has receivedits application of cement or finishing medium.

Preferably the form or last is to be heated before the assembled partsof the shoe upper are placed upon it, whereby the conditioning of thecounter or box toe is begun as soon as the upper has been shaped aboutthe form.

Another object of the invention is to provide an improved support orrack adapted for use in carrying out the above method. Accordingly, theinvention includes a rack for holding one or more of the heat conductingforms or lasts referred to above, the rack having a series of pinsadapted each to be slidably received in a socket in a form or last andmeans for heating each pin whereby the forms or lasts supported by thepins are heated also.

With a View to obtaining the most efiective transfer of heat to thelast, the invention provides as another feature the combination of alast pin mounted on a bar adapted to engage the top of the cone portionof the last on the pin and a heating unit mounted in heat exchangerelation with respect to the bar and pin. Thus, the additional area ofcontact provided between the cone of' the last and the bar furtherinsures an effective transfer of heat to the last.

These and other features of the invention will be apparent from thefollowing description of an illustrative embodiment of the inventionshown in the drawings, in which Fig. l is a perspective view of asupport or rack constructed according to the invention;

Fig. 2 shows in side elevation a shoe form or last, the heel part ofwhich and a pin bar on which the last is supported being shown in crosssection; and

Fig. 3 is a view similar to Fig. 2 showing a different form of pin bar.

The illustrated shoe support or rack comprises a frame ii] carrying astrut l2 at each end on which are mounted a plurality of pin bars M, thenumber of which depends on what capacity the rack is to have. Each pinbar has a plurality of pins l6 extending upwardly therefrom and adaptedto be received in a socket in a form or last l8 rovided by a thimble 20which is attached rigidly to the heel part of the last.

The purposes of the invention are furthered, as

will be pointed out below, by the use of a last having good heatconductivity, and to this end the last l8, as illustrated herein, ismade of metal, aluminum being suitable for this purpose because of itslightness, although other metals or even a non-metallic material such,for example, as moldable material, may be used to advantage.

When the last I3 is placed on the pin iii a substantial area of the topof the cone portion 22 of the last engages the upper surface of the pinbar M, the different lasts on the pin bar being held in parallelrelation and out of contact with each other by studs 24 fixed to the pinbars It, each stud being arranged to fit a hole 26 bored into the topsurface of the cone of the last adjacent to the thimble 20.

The pin bars M and pins i6 also are made of heat conducting material andare heated to a temperature substantially above normal room temperatureby electric resistant heating units 28, which extend throughout thelength of the pin bars M and are fixed to the bottom surfaces thereof.Electric power is supplied to the units 28 through a conduit 30 whichruns from a rheostat 32 by the use of which the amount of currentflowing through the heating units may be controlled so as to maintainthe temperature of the pin bars l4 and pins it high enough to heat thelasts thereon sufficiently to activate or dry cements used in shoemakingor to cause rapid drying of finishing medium and mulled shoe parts.

The invention also provides as illustrated Fig. 3 a tubular or hollowtype of last pin 34, in the interior recess of which is mounted anelectric heating unit 38, and which may be used instead of or with theunit 28 (Fig. 2) un er the pin bar M.

It will now be understood that when the rack is connected to a source ofelectric power the pins E6 or 34 and the pin bars M will be heated to anextent depending upon the adjustment of the rheostat 32. Because of thesubstantial extent of contact of the last at the thimble 28 and coneportion 22 with the pins IE or 34 and pin bar M, respectively, the lastl8 will be effectively heated by conduction. Moreover, since the lastitself is made of heat conducting material, the entire last will beheated uniformly and sufficiently to expedite shoemaking operations aswill now be further explained.

In carrying out the method of the present invention the illustratedrack, having thereon a number of lasts i8, will be connected to a sourceof electric power at a location in the factory where a succession ofoperations begins throughout which the last and shoe thereon is to bemaintained in a heated condition. The last and shoe thereon may beheated at a stage in the manufacture of the shoe even as early as theassembling or lasting operation since the use of heat at this stage willbe beneficial in forming or setting the box toe, depending upon the typeof box toe being used. Similarly, the setting of cements which may beused at this stage of the manufacture of the shoe, as in connection withthe box toe or counter, is also expedited. In accordance with the methodof this invention the lasted shoe, during the intervals betweensuccessive operations on the shoe, will remain on the rack and hencewill be kept at a substantially uniform temperature. Moreover, sinceindividual shoemaking operations are relatively short and because of thesubstantial heat content of the last, no material drop in thetemperature of the shoe will occur while it is being operated upon.Immediately following the end of each shoemaking operation the lastedshoe is replaced upon the rack and the rack is disconnected from thesource of power only during that short interval required for themovement of the rack from the location of one operation in the factoryto the next.

The use of the method and rack of the present invention materiallyreduces the amount of time required to manufacture a shoe because itminimizes delays which ordinarily are occasioned by Waiting for mulledshoe parts, and surfaces to which liquid finishing medium has beenapplied to dry. For example, no time is lost after a mulled outsole hasbeen attached to the shoe in waiting for the outsole to dry. The timerequired by an operator to reach any shoe because of a normalaccumulation of work to be done, is sufiicient when the last and shoeare heated in accordance with the invention, to dry the shoe adequatelywithout delaying the next operation. Similarly, in connection with theoperations of bottom and edge finishing, the rapidity with whichfinishing materials dry after being applied to the shoe in a heatedcondition, permits the operator to present the first shoe in a rack tothe finishing machin immediately after applying the finishing medium tothe last shoe in the rack.

Thus, the practice of the present invention'insures against interruptionin the flow of shoes through the various stages of their manufacture,and minimizes the congestion of racks of shoes awaiting operations whichcannot be performed until a previously mulled or moistened shoe part hasdried.

Furthermore, the final treating operation is greatly facilitated oreliminated as a result of the application of heat to the lasted shoebeing extended throughout a substantial proportion of the time duringwhich the shoe is on the last. That is, the shrinking effect produced bythe heat of the last causes all parts of the upper to be drawn closelyabout the last with a uniform pressure and the duration of the heatingperiod is sufiicient to permit the upper to take a permanent set in theexact form of the last.

Having described my invention, what I claim as new and desire to secureby Letters Patent of the United States is:

1. That improvement in methods of shoemaking which consists inassembling upper and bottom parts of a shoe on and shaping them about ashoe last made of heat conducting material and having a socket adaptedto receive a heated jack pin, performing a succession of differentoperations on the shoe on the last, placing the last on a heated jackpin between consecutive operations whereby the temperature of the lastand shoe is maintained substantially constant throughout the intervalduring which the operations are performed, and moving the jack pin andlast thereon from the site of one operation to that of the succeedingoperation between said operations.

2. In a rack adapted to support heat conducting shoe lasts each having asocket in its cone portion adapted to receive a jack pin, a plurality ofrecessed heat conducting pins adapted to be received in the sockets ofsaid lasts, a heat conducting member on which said pins are mounted,said member being arranged to engage the tops of the cones of lastsmounted on said pins, and means for heating said pins and membercomprising electric resistance units centained in the recesses of saidpins.

3. A support for a heat conducting shoe form having a thimbleconstructed and arranged to receive a jack pin, said support comprisinga pin adapted to be received in said thimble, an electric resistanceheating unit mounted in heat-exchange relation with respect to said pinto heat said pin and a form thereon, and means for controlling thetemperature of said heating unit.

4. A support for a heat conducting shoe form having a socket constructedand arranged to receive a jack pin, said support comprising a recessedpin adapted to fit closely within said socket, and an electricresistance heating unit mounted in the recess of said pin for heatingthe latter and a form supported thereby.

5. A support for a heat conducting shoe form having a thimble in itscone portion, said support comprising a heat conducting bar having a pinmounted thereon, said bar being adapted to engage the top of the cone ofthe form when said pin is inserted in said thimble, and an electricresistance heating unit mounted in heat-exchange relation with respectto said bar and pin for heating the bar and pin and a shoe formsupported thereby.

GEORGE F. RYAN.

CERTIFICATE OF C ORRECTI ON PatentNo. 2,29L L 81. 7 September 1, 191;.2.

GEORGE F. RYAN.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,second column, line 57, for "treating" read treeing-; and that the saidLetters Patent should be read with this correction therein that the samemay conform to the record of the case in the Patent Office.

Signed and seal ed this 17th dey of November, A. D. 1914.2.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

